This invention relates to a magnetic head used in a magnetic reader.
A magnetic head of a magnetic reader adapted to read out data stored on a magnetic storage medium is well known. An example of a conventional magnetic head as is used for a magnetic card reader 70 will be described hereunder in reference to FIG. 7. The magnetic card reader 70 reads data from a magnetic stripe of the magnetic card 71 through a magnetic head 72 coming in contact with a surface of the magnetic card 71 passing through a guide groove (not shown) of the magnetic card reader 70. The magnetic card reader 70 comprises the magnetic head 72, an A/D converter 74 connected to the magnetic head 72 via an interface cable 73 and a control unit 76 connected to the A/D converter 74 via an interface cable 75.
The magnetic head 72 has a core and a coil wound around the core. The control unit 76 is a computer having a CPU, a memory, a hard disc, a CD-ROM drive and a floppy disc drive. Though not shown, a display (display device), a keyboard (input device) and a printer (output device) are connected to the control unit 76 via interface cables.
As the magnetic card 71 with the magnetic stripe passes through the guide groove of the magnetic card reader 70 by the distal end (core gap) of the magnetic head 72, a magnetic flux changes around the core and thereby an induced electromotive force is generated so that an electric current flows in the coil to cancel a variation of the magnetic flux. The current flows from the coil to the A/D converter 74 via the interface cable 73 and is detected by the A/D converter as analog signals. The A/D converter 74 converts the analog signals input from the magnetic head 72 to corresponding digital signals. The digital signals are output from the A/D converter 74 to the control unit 76 via the interface cable 75. The control unit 76 amplifies the digital signals and outputs the digital signals via the display and/or the printer in the form of character data and/or print data, respectively. Furthermore, the control unit 76 stores the data in the form of digital signals in its memory.
The magnetic card reader is generally classified into the reader of manual slide type in which the magnetic card is manually moved along a guide groove and the reader of electric motor-driven insertion type in which the magnetic card inserted into a card inlet is moved by a driving belt or a driving roller.
With the magnetic card reader 70 shown in FIG. 7, if any devices are connected to the interface cables 73, 75, it is possible that the analog signals through the magnetic head 72 might be illegally read out via the cable 73 or the digital signals converted by the A/D converter 74 might be read out via the cable 75. It is also possible that the data stored in the memory might be illegally read out via the cables 73, 75. Both writing and reading data in and from the magnetic card are relatively easy in view of the method of recording on the magnetic card. Accordingly, the magnetic card would be easily duplicated using the data in the form of analog or digital signals which is illegally read out.
It is an object of this invention to provide a magnetic head for a magnetic reader improved so as to make it difficult for others to read out data illegally in the process of reading data from a magnetic storage medium and so as to encrypt the data in order to make the data unavailable to others even if the data is illegally read out.
According to this invention, there is provided a magnetic head of a magnetic reader adapted to read data from a magnetic storage medium.
The magnetic head comprises a core with a coil adapted to sense the data stored on the storage medium in the form of analog signals, an A/D converter chip electrically connected to the coil and adapted to convert the analog signals to corresponding digital signals and an IC electrically connected to the A/D converter chip and adapted to encrypt the digital signals.
This invention includes the following embodiments. The magnetic head further comprises a housing defining an outer peripheral surface of the magnetic head and containing therein the core, the A/D converter chip and the IC.
The A/D converter chip and the IC are fixed within the housing by means of a synthetic resin.
The magnetic reader includes a node terminal adapted to decrypt the digital signals having been encrypted by the IC and electrically connected to the IC of the magnetic head.
The IC is selected from a group including a microprocessor, a gate array, a field programmable gate array and a dedicated hard ware.
The magnetic storage medium is a magnetic card and the magnetic reader is a magnetic card reader.